The present disclosure relates to illumination systems for reduction-optics type scanners. Reduction-optics scanners typically use a cold cathode fluorescent (CCFL) bulb to provide the high illumination level required to generate an adequate signal when scanning an image. It is well known that CCFL bulbs typically require significant warm-up time (e.g. in the range of tens of seconds) and sometimes have problems with output stability. That is, the light output can vary with time and with position along the bulb.
One possible alternative to CCFL illumination systems for optical scanners is to use LED's for illumination. In recent years, high power bright white LED's have been developed. LED illumination offers the potential benefits of “instant on” functionality and consistent output levels, given proper thermal design. However, the use of LED's as an illumination source for a reduction optics type scanner can involve design compromises that cause some light not to reach the target area. One challenge to using bright white LED's in this sort of application is to achieve total light output that substantially matches a CCFL system, while also being cost effective.